In the competition for best streaker ever, I'm torn between this choice, which gets points for the impact the streak has on the news reporter, & this one, which has the added bonus of unlikely athleticism. Both links go to embedded video, both found via this page, which details the revised rules of streaking).
British Adidas commercial (warning QT direct link) featuring soccer players on a field made only of the chalk outlines, floating in a void. I'm guessing this won't get shown in the U.S. due to the relative low profile soccer has here, but it's a great spot. More on the "making of" here.